Ofcom refuses to interfere on powerline networking interference

Powerline Telecommunications kit fails EU standards, but Ofcom tells us there's no proof of interference - and even if there was it couldn't do anything. And even if it could, it wouldn't.

Despite being forced to publish its own study of PLT kit, which showed that devices in popular use generate levels of interference higher than permitted by EU standards, Ofcom tells us it is powerless to prevent them being sold or used. Even if it could it would be beyond the regulator's remit, it says, to bring a criminal prosecution just because "one man cannot pursue their hobby".

PLT involves sending radio signals over mains electrical wiring for home networking, but given the lack of shielding on electrical wiring those signals tend to leak out and can interfere with anyone else trying to use the same frequency. Currently that only hits radio amateurs and those listening to shortwave radio, but faster PLT kit goes higher up the dial and has attracted concern from the Civil Aviation Authority as well as taking out DAB broadcasts and MW transmissions too, though Ofcom claims not to have received a single complaint along those lines.

This is less surprising when one remembers (or is reminded) that complaints about radio reception now go direct to the BBC, which will only pass them on to Ofcom after advising the complainant that they may be billed for the resulting investigation, and telling them that Freesat and/or Cable will make the problem disappear.

Checking complaints made to the BBC, thanks to an FoI request made by Mark Salter, we see that PLT kit is the cause of some complaints, and could be the cause of many others, but the regulator maintains that none have been passed on to it.

Ofcom would not be able to do anything even if complaints were passed on. The problem is that while the kit clearly fails the EU standards, those standards are embodied in UK law with the Electromagnetic Compatibility Regulations 2006, which provide no strict limits on emissions and only requires that "the electromagnetic disturbance [the kit] generates does not exceed a level above which radio and telecommunications equipment or other equipment cannot operate as intended".

This is obviously much harder to test for than proper numbers. Ofcom pointed out to us that a mobile telephone causes clicking in amplification circuits when placed nearby, potentially breaching the rules; but rather than banning mobiles we all just got used to moving our handsets away from microphones, and manufacturers got better at shielding amplifiers.

To successfully prove a criminal case Ofcom would have to demonstrate that PLT kit was causing interference that prevents other equipment operating as intended. The manufacturer could reasonably ask why mobile phones, electric drills and starter motors are still permitted when they can generate similar levels of interference. The difference, obviously, is in the quantity and strength of that interference, but UK law makes no measurement of that.

Ofcom therefore denies there is any problem. Europe is apparently debating bringing in some laws on uncontrolled radio emissions, but until that happens the regulator can't, and won't, do anything about it. ®